chore(NODE-6844): modernize defer and remove incorrect usages

[nbbeeken]

Description

What is changing?

• Add validation to defer to prevent incorrect usages
• Use async/await to get stack traces
• remove incorrect usages

Is there new documentation needed for these changes?

What is the motivation for this change?

The defer usages were passed a promise instead of a functiont that creates a promise.

Double check the following

• Ran npm run check:lint script
• Self-review completed using the steps outlined here
• PR title follows the correct format: type(NODE-xxxx)[!]: description
  • Example: feat(NODE-1234)!: rewriting everything in coffeescript
• Changes are covered by tests
• New TODOs have a related JIRA ticket

[baileympearson]

I think you mentioned over slack yesterday that the changes in this PR were motivated by a flaky change stream test. Is that correct?

Was this the test?

   1) Change Streams
        should properly handle a changeStream event being processed mid-close
          when invoked with callbacks:

If so, it is still failing in CI.

[nbbeeken]

https://mongodb.enterprise.slack.com/archives/GGWBN4ZNK/p1741725536756809?thread_ts=1741723927.759519&cid=GGWBN4ZNK

Similar but a different one

[baileympearson]

Flaky tests tracked in other PRs